Variability Of Clopidogrel Resistance In 200 Patients Undergoing Percutaneous Coronary Intervention

Objective:To compare the variability of clopidogrel resistance in different types of coronary heart disease sufferers undergoing percutaneous coronary intervention and correlation analysis was made between the variability and the MACE.Methods:The study population included 200 patients(Stable Angina Pectoris, n=50;Unstable Angina,n=50;ST-elevated Myocardial Infarction,n=50; Not-ST-elevated Myocardial Infarction,n=50)admitted to the Department of Cardiology in the First Affiliated Hospital of Kunming Medical College from January 2008 to December 2008.All patients received a 300-mg loading dose of clopidogrel(trade name:Plavix).The ADP-induced MPAR were measured by light transmittance aggregometry at baseline and at 12 hours and 5 days.PAC-1 and CD62P were assessed by whole-blood flow cytometry at the same time points.Patients having＞10%inhibition of platelet aggregation were defined as normal responders,whereas those having≤10%inhibition were clopidogrel resistance patients.Platelet function was compared in patients.The recurrence of the MACE were also compared at 30-day and 6-month follow-up after percutaneous coronary intervention.Results:The ADP-induced MPAR were similar in all patients at baseline (P＞0.05).At 12 hours the incidence of clopidogrel resistance:28.00%in all patients, 34.67%in ACS patients,46.00%in STEMI patients,38.00%in NSTEMI patients, 20.00%in UA patients,8.00%in SAP patients.At 5 days the incidence of clopidogrel resistance:23.00%in all patients,28.67%in ACS patients,40.00%in STEMI patients,32.00%in NSTEMI patients,14.00%in UA patients,6.00%in SAP patients.Platelet expression of CD62P,PAC-1 and MPAR were decreased at 12 hours and 5 days than at baseline(P＜0.05).The platelet expression of CD62P,PAC-1 and MPAR was increased in ACS patients compared with SAP patients(P＜0.05).The platelet expression of CD62P,PAC-1 and MPAR was increased in STEMI patients compared with UA patients(P＜0.05).The parameters of platelet expression were similar in NSTEMI patients and UA patients(P＞0.05).The parameters of platelet expression were similar in NSTEMI patients and STEMI patients(P＞0.05).Platelet expression of CD62P,PAC-1 and MPAR had a strong positive correlation.There were significant differences in different types of coronary heart disease sufferers in the MACE at 30-day and 6-month follow-up(P＜0.05).Conclusions:Despite routine dual antiplatelet therapy with aspirin and clopidogrel,a considerable proportion patients have a clopidogrel resistance to a 300-mg loading dose of clopidogrel.Platelet activation was increased in ACS patients compared with SAP patients.Platelet activation was increased in STEMI patients compared with UA patients.Platelet expression of CD62P,PAC-1 and MPAR had a strong positive correlation.Individual responsiveness to clopidogrel is not uniform in all patients.The degree of clopidogrel resistance and the recurrence of the MACE were increased in ACS patients compared with SAP patients.The degree of clopidogrel resistance and the recurrence of the MACE were increased in STEMI patients compared with UA patients.There were no significant differences between NSTEMI patients and UA patients.There were no significant differences between NSTEMI patients and STEMI patients.We found a statistically significant relation between the degree of clopidogrel resistance in different types of coronary heart disease sufferers undergoing percutaneous coronary intervention and the recurrence of the MACE.